Thermostat



F. STRAU B THERMOSTAT June 21, 1927.

Original Filed Feb. 2. 1924 IN VEN TOR.

A TTORNE Y.

Patented June 21, 1927 UNITED STATES FRANK S'IBAUB, 0] LOB ANGELEB,CALIFORNIA.

THEBMOBTAT.

Application filed. February 2, 1824, Serial 1T0. 890,118. Renewed lay 2,1927.

This invention relates to thermostats, particularly the typeused inconnection w th gas fired water heatersand has for its principal objectthe PIOVlSlOIl of an eflicient, quick action thermostat.

Another object of the mvention is to provide a thermostat that may bedisposed under a water heater where it is not apt to be damaged, andwhereby it may be placed in close proximity to the burner tosave 1n thefirst cost of gas pipe, water pipe and connections.

Another object of the invention is to provide a thermostat which may beadjusted readily from the exterior thereof.

Another object of the invention is to pro vide a thermostat which may bemanufactured and sold separate and apart from the Water heater and whichis adapted to be readily connected to any of the several types of waterheaters.

Another object of the invention is to provide a thermostat in which thevalve and valve seat are so designed that they will not tend toaccumulate sediment.

Another object of the invention is to provide a thermostat in which thevalve is readily accessible for inspection.

It will be understood in the consideration of the invention that themost practical type of thermostat for gas fired water heaters is that inwhich the expansion and contraction of a metal tube acts through aporcelain rod and a set of levers to operate a gas controlling valve.The levers are of necessity of the compound type and require a pluralityof fulcrums or bearings and must also be subject to careful adjustment.It is an important object of this invention to provide a thermostathaving compound levers in which thermostat the fulcrum points areprovided without the use of through shafts or the like penetrating theotherwise gas tight casing in which such levers are usually housed.

Other objects include the provision of simplicity of design, freedomfrom wear, and accessibility.

Still other objects and advantages will appear hereinafter and will bebetter understood by virtue of the order of their occurrence.

I have illustrated by the accompanying drawings a preferred embodimentof my invention, and in said drawings,

Figure 1, is a view in vertical section of the said embodiment.

Figure 2, is a view in end elevation thereof with the end closure plateremoved, and

Figure 3, is a plan view thereof.

Figure 4, is a view in section seen on a line 44 of Fig. 1.

More specifically, in carrying out my invention in this embodiment, Iprovide a as tight casing 5, enclosing a substantia ly cubical leverchamber 6, and a valve chamber 7, communicating with the latter througha port 8. Said port is fitted with a removable annular sharp edged valveseat 9. A valve 10 rests on said seat and is provided with a dependinghexagonal guide 11,whereby upon the valve being raised from its seat gasmay flow from the valve chamber to the lever chamber. The latter isprovided with a gas outlet 12, into which is screw threaded a gas pipe13, which is connected to the gas burner (not' shown). The valve chamberis provided with a as inlet port 14 into which is screw threaded a gasinlet pipe 15.

In the embodiment illustrated the valve chamber is vertically disposed,as is also the valve seat, while the major axis of the lever chamber ishorizontal. An upper wall 16 of the casing is provided with a verticalboss 17, into which is screw threaded a copper thermostat tube 18,having a closed end 18. Within the tube a porcelain thermostat rod 19 isprovided, having its lower end 19 extending into the lever chamber. Anipple 17 is pressed on the thermostat tube in abutment with the boss17. A pipe 20, for instance, attached to the thermostat casing by saidnipple can thereby provide the means whereby the thermostat is connectedwith a storage tank (not shown), so that the coolest water in the tankwill gravitate into the pipe and surround the thermostat tube.

Upon cool Water coming in contact with the thermostat tube the latterwill contract, thereby forcing the porcelain tube downwards. To causethecontraction to be multiplied in effect and to act on the valve toraise it from its seat, I provide levers 23 and 23.

Lever 23 is hereinafter known as the primary lever and rests on aknife-like ridge 24, which is an integral art of a circular plug 25.Said plug is tted loosely in a vertical bore 26, leading from theexterior of the easing into the lever chamber. This bore is screwthreaded and therein is fitted a screw adjustment plug 27, accessiblefrom the exterior of the casin Gravi holds the loose plug u n the ajusting p ug.

The lower en of the porcelain rod abuts the rear end 29 of the lever 23,which is formed with a slight concavity 30. Like- Wise, 8. de ression 31of suitable angularity is provided in the lever where it rests on theloose plug. In other words, the lever 1s adapted to rock on an a{)ustable fulcrum, while the porcelain rod a uts its extreme end to therear of the fulcrum. Contraction of the thermostat tube obviouslyresults in the rear end of the primary lever being depressed a slightdistance, while the forward end of the primary lever is raised a greaterdistance.

A salient feature of my invention resides in the fact that the lever 23,hereinafter known as the secondary lever is carried sole-' ly by, theprimary lever and by nothing else, and is fulcrumed thereon, as by a pinprimary lever and extends 32. Said pin is supported by spaced uprightears 33 integral with the primary lever. Said secondary lever parallelsthe rearwardly inthe lever chamber, may be said to extend forwardly.

he lever chamber is closed at one end by a removable closure plate 33'.Said plate being removable permlts of access to the said chamber forassembly, inspection or repair, and thereby the plate ma be readilymachined in manufacture. T e plate is provided with a transverseabutment surface 34, formed in this embodiment by providing a roove 34'therein.

ow a short end 35 extends forwardly from the secondar lever while thelon rearwardly extending end passes below an in proximit to thedepending portion of the valve. he said short end of the secondary leveris arranged to abut said surface whenever the primary lever is raisedsufficiently.

In the operation of my improved thermostat contraction of the tube willresult in the forward end of the primary lever being raised gradually asthe tube slowl contracts by contact with cool water. he upward movementof the forward end of the primary lever results in the latter carryingthe secondary lever upward while said sec ondary lever is resting uponthe primary lever. The figures show the parts in the position which theyassume just before the short end of the secondar lever abuts the saidabutment surface; en the right hand end of the primary lever 23 movesupwardly,,the secondary lever 23 is carried bodily until its end 35comes in contact with the abutment 34. .The abutment 34 is a fixed pointand holds the end 35 against movement. The force which causesturndprimary' while the primary lever stat may be adjusted as desireding movement of the secondary lever 23' is applied through the point 32by the primary stop. Thus the device em loys only primary leverage untilimme iatel rior to the abutmentpf the lever 23' wit t e valve stem. Theresultant action is more rapid and positive than would be the case-ifthe a secondary lever were constantly against the abutment. Therefore,the free end of the secondary lever moves with relatively great velocitand quickly and easily raises the valve rom its seat. Upon expansion ofthe copper tube the action is reversed and the va ve closes result ofthe action of the levers in improved thermostat is, for all practicapurposes, as sensitive and eflicient as the so called sna actionthermostat and far less costly and lntricate. My improved thermobyturning the screw plug in the correct direction. The act of screwing theplug inwardly, for example, forces the levers nearer to the valve, andadjustments may be made readily at any time.

It will be apparent now that I have provided a simple and quick actingthermostat which may be readily adjusted and readily assembled, repairedor inspected, and in which the levers are so mounted that friction isminimized and tendency of the valve and levers to become fouled orjammed, is practicall obviated.

And w ile I have shown and described a specific embodiment of myinvention, I do not limit myself in the construction and arrangements ofparts, and may alter same as I desire without enlarging the scope of asreadily as it opened. As a my invention, within the appended claims.

said plug and disposed within said casing,

a primary lever in said casing mounted on said fulcrum element, athermostat rod vertically disposed with lever, a secondary everfulcrumed on said primary lever, and a sto element carried by saidclosure dispose in the path of movement of an end ofsaid secondarylever.

2. In a thermostat, a primary lever asecondary lever carried bodily byand fulan end restmg on said crumed on said secondary lever, anad'ustable fulcrum for said primary lever, a xed non-adjustable abutmentmember disposed to be abutted by one end of the secondary lever, a valvedisposed to be abutted by the other end of the secondary lever; thelevers, valve and abutment member so positioned with regard one another,when the parts are in normal osition, as to cause the secondary lever toa ut the valve practically immediately after it abuts the abutmentmember.

3. In a thermostat, a casing having a bottom wall and enclosing a gastight space,

15 a fulcrum member vertically adjustable through the bottom wall, aprimary lever held by gravity on said fulcrum, a vertical thermostat rodsupported by sald primary lever, a second lever carried bodily by andfulcrumed to said primary lever; both levers being substantiallyhorizontally disposed and held by gravity in normal position, a verticalvalve having a stem depending into the gas tight space in position to beabutted by one end of said secondary lever, and a non-adjustableabutment internally of the gas tight space adapted to be abutted by theother end of said secondary lever.

FRANK STRAUB.

